Apparatus for feeding blanks having a window opening



Jan. 25, 1966 APPARATUS FOR Filed May 1, 1964 K. STEMMLER 3,231,262 FEEDING BLANKS HAVING A WINDOW OPENING 2 Sheets-Sheet l &

Jr: venfor: (Mr ire/#1451? MQMMW K. STEMMLER APPARATUS FOR FEEDING BLANKS HAVING A WINDOW OPENING Filed May 1. 1964 2 Sheets-Sheet Jn yen/0r: Auer fry/r14 ER firrbR NE vs United States Patent Ofilice 3,231,262 Patented Jan. 25, 1966 3,231,262 APPARATUS FOR FEEDING BLANKS HAVING A WINDOW OPENING Kurt Sternmler, Irlich, near Neuwied, Germany, assignor toRichard Winkler and Kurt Dunnebier, both of Neuwied, Germany 1 Filed May 1, 1964, Ser. No. 364,265 Claims priority, application Germany, June 25, 1963, W 34,759 7 Claims. (Cl. 271-2) The invention relates to an apparatus for feeding blanks with a window opening on machines for the production of envelopes, fiat bags or the like wherein the bottom sheet is withdrawn individually, in known manner, from a pile of blanks which have previously been stamped out as regards their external shape, including the window opening, below the pile and right into the machine. With such a feeding in of blanks with an open Window, that is to say not with a transparent foil stuck over it, there is a risk that while the bottom blank is being pulled away below the pile, the edge of the window opening of the bottom blank which is to the rear in the direction of feed may catch the front edge of the Window opening of a superimposed blank and tear the paper.

The object of the invention is to overcome this difficulty which has long been known. The object of the invention is achieved as a result of the fact that guide members, which are controlled in time with the feeding in of the blanks, are introduced into the window openings in the pile for edges of the windows of superimposed blanks which are moved relatively to one another and, after the window edges of the withdrawn blank have travelled past those of the superimposed one, are moved out of the window openings again and out of the path of the withdrawn blank at a higher speed than the speed at which the blanks are fed in.

Tongues are preferably provided as guide members in the apparatus, which tongues are moved into the window openings in the pile of blanks in the opposite direction to that of feed, before the feed begins, and are moved out again after the rear edge of the window of the withdrawn bottom blank has slid past below the front edge of the window in the superimposed blank which edge is secured by the tongues.

The tongues forming the guide members may be constructed in the form of leaf springs and be secured to a rocker arm controlled by a cam. In this case, a guide unit, which consists of a curved guide for the spring, a roller rotatable on a pin, and a holder and which is mounted by means of the holder on a cross member of the apparatus, is allocated to each leaf spring. it A A supporting plate, which compensates for the height of the holder and engages round the slots in the pile plate may conveniently lie on the pile plate as a seating for the lateral and rear portion of the pile of blanks. The tongues, the guide units for the tongues and the shafts together with the rocker arms secured thereto and the members for controlling the movement of the tongues are preferably constructed in the form of a unit which is displaceable jointly in the direction of feed in relation to the pile plate.

The drawings represent one example of an embodiment of the invention diagrammatically and i FIGURE 1 is a cross section through a pile holder of an envelope machine with the apparatus according to the invention, in section on the line II in FIGURE 2;

FIGURE 2 is a plan View of the pile holder of FIG- URE 1 in the direction of the arrow A;

FIGURE 3 is a partial section on the line III-411 in FIGURE 1 and FIGURE 4 is the side view of a guide unit for the springs, as a detail.

As illustrated in FIGURES l and 2, the pile holder consists of the pile plate 1 which is secured to the two transverse members 2 and 3. The two transverse members may conveniently be mounted on the side walls, not illustrated, of the envelope machine in such a manner that a certain displacement of the whole pile holder transversely to the feed direction is possible in the direction of the two-faced arrow B. Two bars 4 serve to strengthen the pile plate 1. In the usual manner, two feed discs 5 are mounted above the pile plate, two feed segments 6 on the shaft 7 below the pile plate and tworubber roflers 8 which touch the feed segments at maximum diameter thereof. The feed discs 5 and the feed segments 6 rotate at the same speed in the direction of the arrows.

Two bearing members 9 are secured below the pile plate 1 or its bars 4 by means of screws 10 and are rigidly connected to one another by a cross member 34. After the screws 10 have been loosened in the slots 11 in the pile plate, the bearing members 9 can be displaced to a certain extent in the feed direction. The two shafts 12 and 13 are mounted for rotation in the bearing members d. Secured to one end of the shaft 12 is a chain wheel 14 which drives the shaft 12 through the chain wheel 15 secured to the shaft 7 of the feed segments 6 and the roller chain 18 which also runs over the idler sprockets 16, 17, at the same speed as the feed segments 6, in the direction of the arrow. A camplate 19 is secured to the other end of the shaft 12. Fixed to the adjacent end of the shaft 13 is a crank 20 with a follower 21 which is constantly pulled against the cam 19 by a spring which is not illustrated. Clamped to the central portion of the shaft 13 by screws 27 is a rocker arm 22 which is adjustable after the screws 27 have been loosened. In the cylindrical outer surface 22' of the rocker arm, tapped holes 25 are provided for screws 24 by means of which one or more tongue-like leaf springs 23 can be secured at any desired point. The mutual spacing of the leaf springs 23 is equal to the mutual spacing of the slots 26 in the pile plate 1.

A guide unit for each leaf spring 23 is mounted in the respective slot 26 in the pile plate 1. Each guide unit consists of two side walls 28 between which a curved guide 29, a pin 30 with a roller 31 rotatable thereon, and a holder 32 are secured in a manner not illustrated. 'All the guide units are screwed to the cross members 34 of the bearing members 9 by means of screws 33 so that, together with the shafts 12, 13 and the leaf springs 23, they participate in any displacement of the bearing members 9 under the pile plate 1, when this is necessary in view of the position of the window in the blanks.

As can be seen from FIGURES l and 4, the upper surfaces of the side walls 28 and the holder 32 are situated somewhat higher than the upper surface of the pile plate 1. The side walls 28 end in a point at the ends adjacent to the feed segments 5 and 6 in relation to thesurface of the pile plate 1. Above the rollers 31, the side walls are higher by the distance d than the holders 32 at the point designated by 28 (FIGURE 4) substantially in the radius about the center of rotation of the rollers 31. As a result, it is made easier for the leaf springs 23 to raise the edge 38' of the window opening 38 in the blank 37 somewhat, which edge is situated at the front in the direction of feed. Behind and to the side of the slots 26, a supporting plate 35 is preferably provided as a seating for the lateral and rear portion of the pile of blanks 37 and the pile stops, notillustrated. The supporting plate is as thick as the holders 32 project with their surfaces above the pile plate 1.

The apparatus works as follows: The feed discs 5, the feed segments 6 and the cam 19 rotate at the same speed in the direction of the arrows shown. As a result of the follower 21 hearing against the cam 19, the rocker arm 22 executes a rocking movement, in the direction of the two-faced arrow, shown with an intermediate pause. As a result, the leaf springs 23, which are arranged in the region of the window opening 38 in the pile of envelope blanks 37, are alternately first advanced between the roller 31 and the part of the cam 29 opposite the roller into the position shown in FIGURE 1, to the highest position inside the window opening in the pile of blanks, and then withdrawn again to such an extent that the ends 23' of the leaf springs are somewhat below the upper edge of the cam 29 or or" the holder 32, that is to say completely outside the feed path of the bottom blank.

When the apparatus is in the position shown in FIG- URE l, the bottom blank is brought in known manner, by means of a suction device not illustrated, into the position 37 where it is below the feed discs 5. On further rotation of the feed segments 6 in the direction of the rarrow, their edges 6 first grip the blank and bend its free end round the rounded portion of the pile plate 1. As soon as the gripping edge 6 of the feed segments presses the blank against the roller 8, the withdrawal of the blank from below the pile begins. At the same time, the ends 23' of the leaf springs 23 controlled by the cam 19 move out of the highest position shown in FIGURE 1 somewhat obliquely in relation to the direction of movement of the bottom blank towards the edge 38 of the window opening in the pile of blanks supported thereby. The camplate 19 is shaped in such a manner that the rear edge 38" of the window opening in the bottom blank which is in motion slides below the leaf springs 23 and below the front edge 38 of the window opening in the stationary blanks without the risk of striking against them, and the ends 23 of the leaf springs are still a distance away from the edge 38' inside the window opening 38 in the pile of blanks, while their movement is accelerated by the carnplate 19. The further acceleration of the leaf springs 23 beyond the feed velocity of the bottom blank brings the ends 23' of the leaf springs out of the path of the bottom blank in good time after the edge 38 of the window opening in the blank which is in motion has passed below the edge 38 of the window opening in the stationary pile of blanks, so that it can be withdrawn completely from under the pile without hindrance. Then the leaf springs 23 move back obliquely upwards, in the opposite direction, into the window opening in the stationary pile, back into their highest position raising the edge 38' of the window opening slightly with their ends 23'. The cycle described is repeated as each successive blank is fed in.

The invention is not restricted to the example of an embodiment which is illustrated purely diagrammatically. In particular, the tongues 23 and the mechanism for their control may be constructed otherwise, the control, for example, in the form of a positive cam or of a linkage or with pneumatic drive, without the basic idea of the invention being abandoned.

What is claimed is:

1. A blank feeding mechanism for feeding pre-cut blanks including an open window and stacked with the windows in substantial alignment to an envelope making machine, said device comprising, in combination, means for withdrawing blanks, one by one, at a predetermined speed from the bottom of the stack by displacing the lowermost blank substantially parallel to the next higher blank, a guide member for guiding the lowermost blank past the next higher blank, said guide member being movable between a first position protruding into the windows of the stacked blanks and a second position withdrawn from the path of the windows and the path of the lowermost blank when and while the same is withdrawn, drive means for moving said guide member between the first position and the second position, and control means for controlling said drive means, said control means controlling the drive means to move the guide member into its first position substantially at the beginning of the withdrawal of the lowermost blank and to move the guide member into its second position substantially when the trailing edge of the window in the lowermost blank passes the leading edge of the window in the next higher blank, the speed of movement of said guide member into its second position being at a predetermined speed higher than the speed at which said blanks are withdrawn.

2. A blank feeding mechanism according to claim 1, wherein said guide member comprises a tongue-shaped element, said drive means moving said element in a direction slanted in opposition to the direction of withdrawal of the blanks, said element when and while protruding into the windows being interposed between the trailing window edge of the lowermost blank and the leading window edge of the next higher blank when and while the lowermost blank is being withdrawn thereby preventing accidental engagement of said window edges.

3. A blank feeding mechanism according to claim 2, wherein said tongue-shaped element is i the form of an arcuate leaf spring.

4. A blank feeding mechanism according to claim 1, wherein said control means comprise a rocker arm, said arm supporting said guide member, and a rotary cam means coacting with said rocker arm for rocking the same in accordance with the rotation of said cam means, said rocker arm being secured to said guide member for moving the same between its first and second position.

5. A blank feeding mechanism according to claim 1, and comprising a guide means for guiding the movement of the guide member between said positions thereof, said guide means including an abutment member, a roller coacting with said abutment member for guiding the guide member therebetween, and a holder supporting said abutment member and said roller, said holder being stationarily mounted.

6. A blank feeding mechanism according to claim 5 and comprising a horizontal table including a slot for passage of the movable guide member, said holder protruding above the level of said table, and a plate including a cutout substantially matching the peripheral outline of the windows in the blanks and supporting the solid rear and side portions of the blanks as seen in the direction of withdrawal of the same, said plate having a thickness substantially equal to the portion of the holder protrud ing above the level of said table.

7. A blank feeding mechanism according to claim 6, wherein said guide member, said holder and said control means are displaceable as a unit in the direction of withdrawal of the blanks in reference to said table.

References Cited by the Examiner M. HENSON WOOD,

ROBERT B. REEVES, Examiner.

JR., Primary Examiner. 

1. A BLANK FEEDING MECHANISM FOR FEEDING PRE-CUT BLANKS INCLUDING AN OPEN WINDOW AND STACKED WITH THE WINDOWS IN SUBSTANTIAL ALIGNMENT TO AN ENVELOPE MAKING MACHINE, SAID DEVICE COMPRISNG, IN COMBINATION, MEANS FOR WITHDRAWING BLANKS, ONE BY ONE, AT A PREDETERMINED SPEED FROM THE BOTTOM OF THE STACK BY DISPLACING THE LOWERMOST BLANK SUBSTANTIALLY PARALLEL TO THE NEXT HIGHER BLANK, A GUIDE MEMBER FOR GUIDING THE LOWERMOST BLANK PAST THE NEXT HIGHER BLANK, SAID GUIDE MEMBER BEING MOVABLE BETWEEN A FIRST POSITION PROTRUDING INTO THE WINDOWS OF THE STACKED BLANKS AND A SECOND POSITION WITHDRAWN FROM THE PATH OF THE WINDOWS AND THE PATH OF THE LOWERMOST BLANK WHEN AND WHILE THE SAME IS WITHDRAWN, DRIVE MEANS FOR MOVING SAID GUIDE MEMBER BETWEEN THE FIRST POSITION AND THE SECOND POSITION, AND CONTROL MEANS FOR CONTROLLING SAID DRIVE MEANS, SAID CONTROL MEANS CONTROLLING THE DRIVE MEANS TO MOVE THE GUIDE MEMBER INTO ITS FIRST POSITION SUBSTANTIALLY AT THE BEGINNING OF THE WITHDRAWAL OF THE LOWERMOST BLANK AND TO MOVE THE GUIDE MEMBER INTO ITS SECOND POSITION SUBSTANTIALLY WHEN THE TRAILING EDGE OF THE WINDOW IN THE LOWERMOST BLANK PASSES THE LEADING EDGE OF THE WINDOW IN THE NEXT HIGHER BLANK, THE SPEED OF MOVEMENT OF SAID GUIDE MEMBER INTO ITS SECOND POSITION BEING AT A PREDETERMINED SPEED HIGHER THAN THE SPEED AT WHICH SAID BLANKS ARE WITHDRAWN. 